Hi guys,Im a newbie and I'm having a 300 gallon fish tank planning to build a raft system with wood and I don't know what size of swirl filter, biofilter and my raft bed I build thanks sumair
I would recommend a media bed as your bio filter. A swirl filter large enough to hold the flowing water for 2 or more minutes will work for large solids filtering. If you aren't stocking heavily you could get by just putting some worms like red wigglers in the media bed to break down the solids. They love fish poop and will eat dead plant roots too.